Field of the Invention
The present invention relates to image capture apparatuses and methods for controlling the same.
Description of the Related Art
Known autofocus (AF) techniques for automatically adjusting the in-focus distance in an imaging optical system based on signals obtained from an image sensor include contrast detection AF (contrast AF) and an imaging-plane phase-difference detection method (phase-difference AF).
The accuracy of these AF techniques (AF accuracy) is affected by the quality of signals obtained from the image sensor. For example, AF accuracy decreases if the exposure level in a focusing area suddenly changes during an AF operation. If the aperture is adjusted while performing the AF operation such that the amount of exposure during the AF operation does not significantly change, the change in the aperture may affect the contrast evaluation value and/or the defocus amount obtained from an image, resulting in a decrease in the AF accuracy.
Japanese Patent Laid-Open No. 2013-242589 proposes that, if an operation to change the aperture is performed during an AF operation, the AF operation is redone to suppress a decrease in AF accuracy due to the change in the aperture.
However, the method described in Japanese Patent Laid-Open No. 2013-242589 has a problem in that the time required by AF lengthens because the AF operation is redone when an operation to change the aperture is performed during the AF operation.